The invention relates to a method for controlling or regulating a vacuum valve that comprises:                a valve body with a valve opening,        a closing member that can be moved between an open position and a closed position over a closing path for closing the vacuum valve and that closes the valve opening in the closed position, wherein at least one elastic seal is pressed onto a seal face,        an actuator for moving the closing member, and        a control device by which the actuator can be controlled.        
Control devices for vacuum valves are known, wherein these control devices control an actuator for opening and closing the closing member and wherein, for activating the actuator, a corresponding operating means, usually compressed air, is fed to this actuator. Here, self-opening and self-closing valves are known in which, in the case of loss of operating means, the open position or closed position of the closing member is maintained by spring elements. In addition to pneumatically driven vacuum valves, electrically driven vacuum valves are also known. It is also known to feed various input signals on the valve state to the control device, in order to realize safety functions, i.e., to prevent or to trigger the opening or closing of the vacuum valve for certain states of the vacuum system.
From U.S. Pat. No. 7,036,794 B2, a method for controlling a vacuum valve is known in which the pressing force acting on the elastic seal is set by the control device as a function of a determined value for the differential pressure between the two vacuum chambers between which the vacuum valve is arranged. In this way, the wear of the elastic seal can be reduced.